1. Field of the Invention
The disclosed technology relates to a method for forming a nanostructure penetrating a layer, to a device formed therewith, and to use of the device.
2. Description of the Related Technology
Nano-structures have been active for years because of their unique properties in the micro-scale. At the micro-scale, nano-structures-based electrical and optical devices can be integrated with biology, for example single molecule detection and DNA identification. In order to reach such a high resolution, a nano-pore or a nano-slit is always a must.
Numerous ways how to make nano-pores have been described by using electron beams (Storm, A. J. et al. Fabrication of solid-state nanopores with single-nanometre precision. Nature Mater. 2, 537-540 (2003)), ion gun (Li, J. et al. Ion-beam sculpting at nanometre length scales. Nature 412, 166-169 (2001)) and many other tools. However, the size and the aspect ratio of the nanopore have been limited by the current technology in nanometer scales. Moreover, these nano-structures are always made by etching technology i.e. e-beam, FIB and etc.
In some cases, Nano-structures including nanocolumn and nanowires can be achieved by selective area growth through the pattern in the mask. Some preliminary results have been shown recently (Xin Wang, et al. APL 89, 233115 (2006), S. Ishizawa, et al Applied Physics Express 1, 015006 (2008), S. Hersee, Nano Lett. 6, 1808 (2006). However, very high resolution e-beam lithography has been applied. Furthermore, the feature size of the nano-structures has been limited by the resolution the e-beam lithography.
WO03/16781 discloses a method of analyzing molecules such as DNA, wherein light is directed to a metal surface of a membrane having one or more apertures. The incident light excites surface plasmons (electron density fluctuations) in the top metal surface and this energy couples through the apertures to the opposing surface where it is emitted as light from the apertures or from the rims of the apertures. The extent to which surface plasmons are induced on the surface at the aperture exit may be limited, thereby constraining the resulting emissions to small target areas. The resulting spot illumination may be used to analyze the properties of small objects such as proteins and nucleic acid molecules and single cells.
It is thus desirable to provide a device with an improved signal to noise ratio.